X05Ni80CP580046 | 58L-402B | Carbon Monoxide 250 PPM | Hydrogen Sulfide 15 PPM | Methane 1.25% Volume [25% LEL] (50% LEL Pentane equivalent) Oxygen 18% Balance Nitrogen contained in a 58L Liter Disposable Aluminum Cylinder, For Use with Any and All Gas Detectors, Cylinder Connection C-10, Calibration Certificate NIST, Made in the USA